Systems and methods of preparing and delivering gels

ABSTRACT

The present disclosure provides systems and methods for delivering a gel to a surface. In one embodiment, the system may have a first vessel with a first low viscosity aqueous solution comprising a binder/crosslinking agent; and a second vessel with a second low viscosity aqueous solution comprising a gelling component. The separate first and second low viscosity aqueous solutions are sprayed onto a surface where the solutions mix forming a gel.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application 62/696,261 filed Jul. 10, 2018, Hutchins et al., which is hereby incorporated by reference in its entirety. The present application is related to co-pending PCT Application No. PCT/US19/41215, filed on Jul. 10, 2019 by inventor James Hutchins, Atty. Dkt. 0010-05-PCT. This co-pending PCT application is incorporated herein by reference in its entirety.

1. FIELD

The present disclosure provides systems and methods for forming a gel on a surface. In one embodiment, the system may have a first vessel with a first low viscosity aqueous solution comprising a binder/crosslinking agent; and a second vessel with a second low viscosity aqueous solution comprising a gelling component. The separate first and second solutions are sprayed, or otherwise applied onto a surface where the solutions mix forming a gel. In addition to systems, methods are also provided. In one embodiment, at least one of the low viscosity aqueous solutions contains a deliverable product of interest, such as a vaccine.

2. BACKGROUND

2.1. Introduction

The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

Gels offer a benefit in that the formulations adhere to a surface and stay where they are applied. A gel will keep a product of interest localized to a particular area. Thus, many medications, preventatives and therapeutic treatments are formulated in the form of a gel. For example, a gel for topical delivery of an anesthetic such as lidocaine will keep the active ingredient localized to a desired area of interest and away from other areas. Water soluble gels also have the advantage of hydrating products that may degrade if they dry out. Typically, biologics and vaccines will be inactivated, or become ineffective upon drying out.

Mixing an active ingredient uniformly in a gel may be difficult. Most gel based applications are manufactured as a gel at production facilities at final concentrations, utilizing automated mixing equipment to ensure uniform dispersion of active ingredients in the gel. Alternatively, some gels may become less viscous on heating which aids mixing, but many products are not compatible with the higher temperatures.

Furthermore, delivery of gels can be complicated due to their high viscosity which complicates some methods of delivery such as spraying and requires high pressures. Improved methods of delivering either gels or gel formulations, containing active ingredients, are therefore needed.

In animal production facilities, such as hatcheries, high-throughput requirements necessitate hundreds of thousands, a million or more subjects be processed each day. These processes may include vaccination. In poultry production facilities, these vaccines are concentrates that require dilution before use. Vaccines are typically prepared in 5-10 L batches. Multiple batches are needed during the course of a day. For some vaccines, dilution into gel is preferred for administration. It is challenging to efficiently mix small vials of concentrated vaccine uniformly into larger volumes of viscous gel. It is easier to mix vials of vaccine into a low viscosity aqueous solution. High viscosity solutions are also difficult to dispense uniformly, due to the high pressures required.

2.2. Vaccines, Apicomplexa, Eimeria, and Coccidiosis

Vaccines are an important component of protecting humans and animals from pathogenic microorganisms, including viruses, bacteria, and parasites. Briefly, a vaccine stimulates the immune system to recognize a specific pathogen, thereby making a defense system that protects against future encounters with that microorganism in nature. Vaccines may be divided into several major classes, specifically; inactivated or killed vaccines, subunit vaccines, wildtype vaccines and attenuated or modified-live vaccines. The wildtype and attenuated vaccines give the recipient animal a mild infection. The mild infection often produces an immune response so as to prevent a greater, perhaps lethal infection from occurring in the future.

Apicomplexa is a phylum of unicellular and spore forming parasites with a complex life cycle. Well-known human diseases caused by apicomplexa include babesiosis (Babesia), cryptosporidiosis (Cryptosporidium parvum), malaria (Plasmodium), and toxoplasmosis (Toxoplasma gondii). Apicomplexan diseases also effect animals and livestock. Some such as Cryptosporidium parvum and Toxoplasma gondii effect both humans and animals. Other apicomplexa such as Eimeria or Theileria only effect animals. The apicomplexa life cycle is complicated in that it has both sexual and asexual reproductive stages. The life cycle often consists of a stage where it is excreted into the environment, and other stages that occur within the animal host. For many apicomplexa some stages of the life cycle take place in one host species and other stages take place in another host species.

On the other hand, the apicomplexan parasite, Eimeria, is generally host specific and is monoxenous, that is the life cycle is specific for a single host species. Sporocysts, a life-stage of Eimeria contained within oocysts, can be released prior to delivery to improve vaccine infectivity. Eimeria causes coccidiosis in the wild and domesticated vertebrates such as cattle, chickens, fish, goats, pigs, rabbits, reptiles, sheep, and turkey. Different Eimeria species have a preferred section of the gastrointestinal (GI) tract where they reproduce and cause damage to the epithelium of the GI tract.

Coccidiosis is a common disease in poultry. Control of coccidiosis has typically been achieved using ionophores or chemicals in the feed. Alternative control measures are currently being sought, due to costs of ionophores and chemicals, consumer demand, and the risk of developing resistant organisms, such as coccidia and others. Vaccines for coccidiosis have the potential to drastically reduce or eliminate the need for ionophores or chemicals in feed for coccidiosis control. However, vaccines are not widely used in part due to the lack of uniformity with mass vaccine application. As presently delivered, Eimeria vaccines in poultry result in inefficient first round infectivity and immunity, and typically result in a large naïve population susceptible to disease. The subsequent naïve population depend on recycling in the grow out farms to induce immunity. Output from birds infected in the first-round yield massive infection of the residual naïve population. Resolution of naivety yields high oocyst output in the period following the first-round infection, which results in susceptibility to secondary bacterial infections, such as necrotic enteritis, requiring antibiotics for resolution. Effective vaccination of all birds at the day of hatch would avoid the morbidity, mortality and lack of weight gain associated with Eimeria infection. See PCT Publication WO 2017/083663A1, Karimpour. Currently the global impact of coccidiosis due to poor performance, morbidity and mortality is estimated at $300 million. In addition, an estimated $90 million is spent in the US and $3 billion globally for coccidiosis control annually (5m Editor, 2013, High Cost of Coccidiosis in Broilers, The Poultry Site, https://thepoultrysite.com/news/2013/02/high-cost-of-coccidiosis-in-broilers).

3. SUMMARY OF THE DISCLOSURE

As opposed to mixing active ingredients into a pre-formed gel, a two-component gel system is proposed. This system consists of two low viscosity aqueous solutions that form a gel upon combining. The advantages of this system are ease of mixing, low pressure delivery and prevention of dehydration at administration.

One embodiment is directed to a system for delivering a product of interest. The system includes a first vessel containing the product of interest in a first solution, a second vessel containing a second solution, a delivery device in fluid communication with the first and second vessels, and a delivery device outlet. The first solution is moved from the first vessel to the first delivery device outlet to create a first spray. The second solution is moved from the second vessel to the second delivery device outlet to create a second spray. Upon delivery, the first and second solutions mix to form a gel containing the product of interest. A second embodiment is directed to a system for delivering a vaccine solution, containing oocysts, to an animal. The system includes a first vessel containing unbroken oocysts in a first solution, a second vessel containing a second solution, a delivery device in fluid communication with the first and second vessels, and a delivery device outlet. The first solution is moved from the first vessel to the first delivery device outlet to create a first spray. The second solution is moved from the second vessel to the second delivery device outlet to create a second spray. Upon delivery, the first and second solutions react to form a gel containing the oocyst solution.

Yet another embodiment is directed to a system for disrupting the outer membrane of an oocyst, releasing at least some intact sporocysts, and subsequently delivering the resulting mixture to an animal. See co-pending PCT Application No. PCT/US19/41178, filed on Jul. 10, 2019, James Hutchins et al. The system includes a first vessel containing unbroken oocysts in a first solution, a processing chamber, and a first delivery device having a first delivery outlet. The system also includes a second vessel containing a second solution, and a second delivery device having a second delivery outlet. The first solution is moved from the first vessel to the processing chamber where at least some of the oocyst membranes are disrupted creating a first solution, which is a mixture of oocysts and sporocysts. The first solution is moved to the first delivery outlet to create a first spray, and the second solution is moved from the second vessel to the second delivery device outlet to create a second spray. The first and second solutions mix upon delivery to form a gel, containing oocysts and sporocysts.

Formulations used for delivery of oocyst-based vaccines may be aqueous solutions or more complex solutions, including gels. Simple aqueous solutions typically provide no components to protect oocysts from drying out after spray application. Gel formulations can protect oocysts from drying out, however, it is difficult to uniformly mix a vaccine into a high viscosity gel, and likewise it may be difficult to dispense the high viscosity product onto the recipients. Processing oocysts to release sporocysts can improve vaccine efficacy, however, as sporocysts are no longer encapsulated within their natural protective carrier, the oocyst wall, it is important to provide a protective environment to ensure viability. To form a protective gel for sporocysts, a two-component system may be used for spray delivery in which both components are low viscosity aqueous solutions as described hereinafter. Upon combining, the components form a protective gel surrounding the sporocysts. This solution avoids the difficulties associated with either mixing vaccine into a viscous solution or dispensing/spraying a pre-mixed vaccine in a high viscosity solution (e.g., a gel).

A preferred commercial bird to be vaccinated by the method of the invention is a chicken.

A preferred composition to be administered to a chicken comprises sporocysts, or a mixture of sporocysts and oocysts, of one or more species of Eimeria selected from the group consisting of E. tenella, E. acervulina, E. maxima, E. necatrix, E. mitis, E. praecox, E. hagani, E. mivati, and E. brunetti.

Another preferred commercialized bird to be vaccinated by the method of the invention is a turkey.

A preferred composition to be administered to a turkey comprises sporocysts, or a mixture of sporocysts and oocysts, of one or more species of Eimeria selected from the group consisting of E. meleagrimitis, E. adenoeides, E. gallopavonis, E. dispersa, E. meleagridis, E. innocua, and E. subrotunda.

4. BRIEF DESCRIPTION OF THE FIGURES

Having thus described various embodiments of the present disclosure in general terms, reference will now be made to the accompanying drawings, which are not drawn to scale and do not include all components of the system.

FIG. 1 is a schematic drawing of the gel embodiment (1).

FIG. 2A is a graphic representation of the life cycle of Eimeria oocysts and vaccines.

FIG. 2B is a graphic representation of the life cycle of Eimeria oocysts in a chicken.

FIG. 3 is a schematic drawing of the gel embodiment (2).

FIG. 4 is a schematic drawing of the gel embodiment (3).

5. DETAILED DESCRIPTION OF THE DISCLOSURE

Various aspects of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all aspects of the disclosure are shown. Indeed, this disclosure may be embodied in many different forms and should not be construed as limited to the aspects set forth herein, rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Like numbers refer to like elements throughout. In the figures, the thickness of certain lines, layers, components, elements or features may be exaggerated for clarity. All publications, patent applications, patents, and other references mentioned herein are incorporated herein by reference in their entireties.

5.1. Definitions

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention.

As used herein the term Eimeria means and includes Eimeria species infecting chickens consisting of E. maxima, E. mitis, E. tenella, E. acervulina, E. brunetti, E. necatrix, E. praecox, E. hagani, E. mivati, and any combination thereof. Eimeria includes species infecting turkeys such as E. meleagrimitis, E. adenoeides, E. gallopavonis, E. dispersa, E. innocua, E. meleagridis, and E. subrotunda, and any combination thereof. Eimeria also includes species infecting cattle such as E. zuernii, E. bovis, E. ellipsoidalis, and any combination thereof. Eimeria also include E. ahsata, E. bakuensis, E. crandallis, E. faurei, E. granulosa, E. intricata, E. marsica, E. ovinoidalis, E. pallida, E. parva, E. weybridgensis, and any combination thereof. Furthermore, the term Eimeria includes E. intestinalis, E. vejdovskyi, E. piriformis, E. coecicola, E. irresidua, E. jlavescens, E. exigua, E. magna, E. perforans, E. media, E. stiedae, and any combination thereof.

The terms “animal” and “animal subjects” include but are not limited to mammalian and/or avian subjects. Suitable mammalian subjects include but are not limited to primate subjects (e.g., human subjects and non-human primate subjects such as simian), porcine, bovine (e.g., cattle), caprine, equine, feline, ovine, canine, murine (e.g., mouse, rat) and lagomorph subjects.

The terms “avian” and “avian subjects” (i.e., “bird” and “bird subjects”), as used herein, are intended to include males and females of any avian species, but are primarily intended to encompass poultry that are commercially raised for eggs, meat or as pets. Accordingly, the terms “avian” and “avian subject” are particularly intended to encompass but not be limited to chickens, turkeys, ducks, geese, quail, pheasant, parakeets, parrots, cockatoo, cockatiel, ostrich, emu and the like. In particular embodiments, the avian subject is a chicken or a turkey.

As used herein, the term “low viscosity” is defined as approximately 1 centipoise at 20 degrees Celsius.

As used herein, the term “preening” or “preen” is defined as the act of a chicken, or other animal, ingesting oocysts, or other materials, through the act of grooming oneself, or another animal, and subsequently consuming the preened material to initiate infection.

As used herein, the term “take”, “percent take”, or “% take”, within the context of vaccine infectivity, is defined as the subject having been shown to be positive for an apicomplexan infection, including but not limited to, Eimeria following vaccination.

As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The present disclosure may suitably “comprise”, “consist of”, or “consist essentially of”, the steps, elements, and/or reagents described in the claims.

It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely”, “only” and the like in connection with the recitation of claim elements, or the use of a “negative” limitation.

As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. As used herein, phrases such as “between X and Y” and “between about X and Y” should be interpreted to include X and Y. As used herein, phrases such as “between about X and Y” mean “between about X and about Y.” As used herein, phrases such as “from about X to Y” mean “from about X to about Y.”

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity. The sequence of operations (or steps) is not limited to the order presented in the claims or figures unless specifically indicated otherwise.

Throughout the present specification, the terms “about” and/or “approximately” may be used in conjunction with numerical values and/or ranges. The term “about” is understood to mean those values near to a recited value. For example, “about 40 [units]” may mean within ±25% of 40 (e.g., from 30 to 50), within ±20%, ±15%, ±10%, ±9%, ±8%, ±7%, ±6%, ±5%, ±4%, ±3%, ±2%, ±1%, less than ±1%, or any other value or range of values therein or there below. Alternatively, depending on the context, the term “about” may mean±one half a standard deviation, ±one standard deviation, or ±two standard deviations. Furthermore, the phrases “less than about [a value]” or “greater than about [a value]” should be understood in view of the definition of the term “about” provided herein. The terms “about” and “approximately” may be used interchangeably.

Throughout the present specification, numerical ranges are provided for certain quantities. It is to be understood that these ranges comprise all subranges therein. Thus, the range “from 50 to 80” includes all possible ranges therein (e.g., 51-79, 52-78, 53-77, 54-76, 55-75, 60-70, etc.). Furthermore, all values within a given range may be an endpoint for the range encompassed thereby (e.g., the range 50-80 includes the ranges with endpoints such as 55-80, 50-75, etc.).

Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Preferred methods, devices, and materials are described, although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure. All references cited herein are incorporated by reference in their entirety.

5.2. Two-Component Gel Embodiments

The present embodiments described below are directed to a two-part gel system. One embodiment uses a two-component system in which neither component is a gel initially, but when combined, form a gel. In a first gel embodiment, a system may be comprised of a first component comprising a gelling component in a low viscosity aqueous solution, such as sodium alginate solution and a second component being a low viscosity aqueous solution containing a binder/cross-linker such as calcium chloride liquid solution. Each spray component is an aqueous solution of relatively low viscosity as compared to a gel, thus facilitating mixing and spraying. When the low viscosity aqueous solutions are sprayed, or otherwise applied, onto a surface of interest and allowed to combine, a gel is formed. The newly formed gel can provide protection of the substance from the environment, resulting in an increase in the time the gel stays on the surface to which it was sprayed.

It is appreciated that the two-component gel system may have many applications including but not limited to the food, agricultural, military, aerospace, chemical, biochemical, pharmaceutical, nutraceutical, cosmetic, printing and manufacturing industries, and any other application where a gel coating or gel application may be used.

Examples of uses of a two-part gel system include herbicide and pesticide applications, paint and other coating applications. Another anticipated application may include a pharmaceutical dermatological preparation being applied in a two-stage process, where a first solution contains a first active ingredient and a second solution contains a second active ingredient. The first solution is applied to the skin followed by the second solution being applied to the skin. Upon mixing, the first and second solutions form a gel but also form a complete dermatological preparation, when the first and second active ingredients mix.

5.3. First Gel Embodiment

The first gel embodiment 100, shown in FIG. 1, includes a first reservoir 12 holding a binding/crosslinking agent in solution 102, this may be a calcium chloride solution, and an outlet 18. The first gel embodiment 100 also includes a pump, (not shown). The first gel embodiment 100 also includes a first delivery device 46 in the form of a sprayer having a first nozzle 50.

The first gel embodiment 100 further includes a second reservoir 86 containing a gelling component solution 90. In one embodiment this may be a sodium alginate solution. The first gel embodiment 100 includes a second delivery device 47 in the form of a sprayer having a second nozzle 51. The second reservoir 86 is connected to the second delivery device 47 by means of a second reservoir outlet 88.

In use, the binding/crosslinking agent in solution 102 is pumped from the first reservoir 12 to the first nozzle 50. The gelling component solution 90 is pumped from the second reservoir 86 to the second nozzle 51. Both solutions 102 and 90 are delivered from the first and second nozzles 50, 51 to a surface 61. In this way, the binding/crosslinking solution 102 mixes upon delivery with gelling component solution 90 on the solid surface 61 to form a gel. The two sprays may be delivered sequentially or simultaneously.

One of ordinary skill would recognize that in an alternative embodiment, the first reservoir 12 may contain the gelling component solution and the second reservoir 86 may contain the binding/crosslinking solution. In this alternative embodiment, when both solutions are sprayed onto a surface 61 they will form a gel at a common location.

As can be appreciated, this first embodiment 100 applies anywhere an aqueous coating is used. As discussed above, this includes applications in the food, agricultural, manufacturing, chemical, biochemical, military, aerospace, nutraceutical, cosmetic, printing and pharmaceutical industries. It is anticipated that the two-part solution described herein may have advantages where one or more of the ingredients in the solution may be reactive to another ingredient in the solution. By applying the gel in a two-part solution, any reactivity may be avoided until the solution has been mixed into a gel form.

5.4. Second Gel Embodiment

Portions of the life cycle of an Eimeria oocyst whether wildtype or attenuated) are illustrated in FIG. 2A & FIG. 2B. FIG. 2A portrays an overview of the external process that occurs with Eimeria oocyst uptake in chickens. The day-of-hatch chicken is first inoculated with vaccine that contains sporulated oocysts (A). The sporulated oocyst is then processed within the digestive tract of the chicken. This process is shown in greater detail in FIG. 2B. The infection continues through multiple life stages, eventually resulting in the formation of unsporulated oocysts that are excreted in the chicken's feces (B). Following excretion from the bird, the unsporulated oocysts are then exposed to heat, moisture and oxygen in the environment, and become sporulated over the course of several days (C). The oocysts are not infective until they are sporulated. These sporulated oocysts are then ingested by the chicken, and the cycle repeats.

FIG. 2B portrays an enlarged view of the internal processes that occur with Eimeria oocyst uptake in chickens. The boxed region shows a simplified depiction of the oocyst reproductive life cycle, wherein the sporulated oocyst membrane, containing four sporocysts, is disrupted, releasing sporocysts (D). Within each sporocyst are two sporozoites. Enzymatic reactions within the bird's intestines digest the endcap of the sporocyst wall (not shown), releasing the sporozoites. The motile sporozoites then seek out and infect intestinal cells (E) in different regions of the intestines in a species-specific manner. For example, in chickens E. acervulina infects the upper intestine, E. maxima infects the small intestine, and E. tenella infects the caecum.

Following infection of intestinal cells by sporozoites, the life cycle of the parasite continues through several stages of asexual reproduction. These cycles consist of several rounds of reproduction and amplification that result in a massive increase in Eimeria presence within their select regions of the intestinal tract. After amplification brought on by the asexual reproduction stages, sexual reproduction occurs and results in the production of oocysts, that will then be shed in the feces of a chicken and consumed by another chicken as depicted in FIG. 2A.

The complete process takes approximately 7 days, with exact lengths of time varying by Eimeria species. The excystation process and subsequent invasion of a host cell occurs between day 0 and day 3. The asexual reproduction cycle occurs between day 3 and day 5. The sexual reproduction phase and subsequent shedding of the oocyst in the feces occurs between day 5 and day 7.

In commercial poultry operations mass application of vaccines may not optimize the frequency of vaccine take, as many birds are missed or partially vaccinated. Mass application is commonly used due to the need for high-throughput and lack of alternative methods of vaccination. A new method of high-throughput, individual vaccination delivered directly to a targeted area may dramatically improve vaccination. See PCT Publication WO 2017/083663A1, Karimpour. When oocysts or sporocysts are sprayed directly into an orifice leading to the digestive tract, such as the eyes, mouth or nasal passages, they are likely to be ingested and processed to the infective sporozoite life stage. Oocysts or sporocysts which are sprayed onto feathers may be subject to a limited time frame of viability because the live oocysts and sporocysts will quickly dehydrate and die if not maintained in an aqueous environment. Viability may be extended if the oocysts and/or sporocysts are enclosed in a gel to limit dehydration. However, spraying a gel is problematic due to high viscosity, as is mixing a vaccine uniformly into a gel.

The second gel embodiment 110, shown in FIG. 3, includes a first reservoir 12 holding an oocyst vaccine solution 82 containing oocysts suspended in a calcium chloride solution. The second gel embodiment 110 also includes a pump, (not shown). The second gel embodiment 110 also includes a first delivery device 46 in the form of a sprayer having a first nozzle 50. The first reservoir 12 is connected to the first delivery device 46 by means of a first reservoir outlet 18.

The second gel embodiment 110 further includes a second reservoir 86 containing a sodium alginate solution 90 and a second delivery device 47 in the form of a sprayer having a second nozzle 51. The second reservoir 86 is connected to the second delivery device 47 by means of a second reservoir outlet 88.

In use, the oocyst-containing calcium chloride solution 82 is pumped from the first reservoir 12 to the first nozzle 50. The sodium alginate solution 90 is pumped from the second reservoir 86 to the second nozzle 51. Both solutions 82, 90 are delivered simultaneously from the first and second nozzles 50, 51 to the facial mucosa of a day-old hatchling for direct ingestion, or other region of the body for preening. In this way, the oocyst calcium chloride solution 82 mixes upon delivery with the sodium alginate solution 90 to form a gel 62. The gel 62 is either ingested by the hatchling upon delivery of the solutions 82, 90 onto the surface of the animal or during preening. The oocysts suspended in the gel 62 avoid dehydration for a longer period of time, which provides further opportunity for the hatchling to ingest the gel and thus the oocysts while preening.

It is appreciated that either the calcium chloride or the sodium alginate solution may be mixed with the oocyst-based vaccine. Moreover, the solutions 82, 90 may be sprayed independently in either order or simultaneously to achieve the same result, namely to form a gel based mixture. In addition, the first reservoir 12 may contain the sodium alginate solution and the second reservoir 86 may contain the calcium chloride solution. The oocysts may be in either of the two components for the gel forming system.

A preferred formulation includes 2% sodium alginate with calcium chloride at between 3 and 4%, most preferably between 3.5 and 3.8%, to ensure rapid formation of gel with sufficient viscosity to maintain encapsulation of oocysts or sporocysts during preening.

Propylene glycol alginate (PGA) may be used as a substitute for sodium alginate. Another alternative formulation to sodium alginate and calcium chloride includes formation of a calcium pectate gel by combination of calcium lactate or calcium gluconate solution with an appropriate pectin-containing solution such as low methoxyl (LM) pectin or amidated low methoxyl (LMA) pectin.

5.5. Third Gel Embodiment

A third gel embodiment 120, shown in FIG. 4, involves the two-component solution described above for the first 100 and second 110 gel embodiments. However, the third gel embodiment 120 incorporates the use of a processing system 24 to disrupt at least some of the oocyst membranes, thus releasing at least some of the sporocysts into one of the two solutions and subsequently delivering the solutions as sprays that form a gel when the two solutions combine. The third gel embodiment 120 includes a first reservoir 12 holding oocyst vaccine solution 82 containing oocysts suspended in calcium chloride. The third gel embodiment 120 also includes a pump 20. A pump outlet 22 is fixed between the pump 20 and a processing system 24.

The third gel embodiment 120 includes a processing system 24 comprising a homogenizer 32. A first nozzle 50 is connected to the processing system 24.

The third gel embodiment 120 further includes a third reservoir 86 containing a sodium alginate solution 90. The third gel embodiment 120 also includes a second delivery device 47 which is a sprayer having a second nozzle 51. The second nozzle 51 is connected to the third reservoir 86. Both the first and second delivery devices 46, 47 are connected to a pressurized air source, not shown.

The inlet for the homogenizer 32 is fluidly connected to the first reservoir outlet 18. The outlet for the homogenizer 32 is fluidly connected to a second reservoir 40, leading to the first delivery device 46. The outlet for the third reservoir 86 is fluidly connected to the second delivery device 47.

In use, the oocyst solution 82 is pumped by means of pump 20 from the first reservoir 12 through the processing system 24. The homogenizer includes a high-pressure source 26, controlled by a pressure valve 28. The high-pressure homogenizer 32 moves the oocysts in solution 82 in through the inlet 36 into the vessel 30. The homogenizer 32 moves the solution 82 through the small orifice (not shown) causing at least some of the oocyst membranes to be disrupted and thus releasing at least some of the sporocysts. The solution is moved through the outlet 38 through the inlet 42 into the second container 40. The oocysts, disrupted membranes, and sporocysts in solution with calcium chloride result in an amended solution 85. The amended solution 85 is moved directly to the first nozzle 50.

In an alternative arrangement, the high-pressure homogenizer 32 may be directly connected to the delivery device 46. In this way, the solution produced by the homogenizer 32 is delivered directly rather than temporarily stored in the second reservoir 40.

When an animal, particularly a day-old hatchling, is to be sprayed, the first and second nozzles 50, 51 are opened. Pressurized air at both the first and second nozzles 50, 51 creates respective spray profiles of both solutions 85, 90 which combine at the surface of hatchling and form a gel. When both solutions 85, 90 mix on the hatchling, they form a gel 87 containing oocysts and released sporocysts. This gel decreases the rate of dehydration and increases the opportunity for ingestion by the animal through further preening. Preferably, the solutions 85, 90 are sprayed onto one or more mucosa areas of the hatchling, namely the eyes, and/or beak.

As stated above with regard to the second 110 or third gel embodiment 120, it is appreciated that either the calcium chloride or the sodium alginate solution may be mixed with the oocyst-based vaccine prior to being pumped through the delivery devices. Moreover, the solutions 85, 90 may be sprayed independently in either order or simultaneously to achieve the same result, namely, to form a gel-based mixture on the surface of the animal subject that has been sprayed.

It is further appreciated that while the third gel embodiment 120 has been described with the homogenizer 32 as the processing system 24, it is anticipated that other processing systems may be substituted to obtain the amended solution 85 of the third gel embodiment 120. It is also appreciated that while the third gel embodiment 120 described above involved solutions 85 and 90 being moved directly from the processing system 24 and third reservoir 86 respectively, it is appreciated that either or both solutions 85, 90 could be first moved to a temporary holding tank prior to delivery, as shown and described in FIG. 4. See PCT Application No. PCT/US19/41178, filed on Jul. 10, 2019, James Hutchins et al., for additional processing systems.

It should also be noted that all embodiments described herein may be applied to an animal individually or en masse. It is appreciated that the embodiments described herein may be applied to a large group of hatchlings, or other animals, contained in a crate or other container and subject to delivery of solution in a gel form, as described in gel embodiment (1), (2) or (3).

The systems and methods disclosed herein may be adapted for use in aquaculture. Gel beads containing nutrients, medications, or vaccines may be produced in situ and introduced into fish tanks, or open water containing farmed fish for consumption. Examples of Eimeria which infect fish include, but are not limited to, E. aurati, E. baueri, E. lepidosirenis, E. leucisci, E. rutili, and E. vanasi. Shearing processes may be applied to these species where applicable to facilitate release of more infective life stages for the purpose of vaccination. A vaccine for Eimeria which infect fish may be administered using the gel forming process with gel beads distributed into tanks or waters for consumption by fish.

5.6. Applications of the Two-Component Gel Method

Formation of protective gel coatings in situ by combination of two low viscosity components may benefit diverse applications such as frost protection of plants or wound dressings for humans or animals. Drones may incorporate vision systems with on-the-fly two-component gel delivery specifically and efficiently to whole plants or trees or even individual plant blossoms in an orchard or to affected or injured animals in a herd. The low viscosity of the individual liquid components would facilitate low pressure delivery, compared to higher pressure systems which would be required to deliver a gel directly.

The gel system could be used as a frost-protectant system for plants, administered in spray bottles on a small scale or by drones on a commercial scale. The system could be used to deliver medicaments to individual animals in herds. Vaccines or medicines could be delivered to herds of livestock species such as, cows or horses, by drones. The system could potentially be used to deliver medicines to humans. Applications could include wound or burn treatment. One advantage of a two-component gel delivery for treatment of wounds or burns would be to minimize the contact and/or abrasion of sensitive tissues. For a burn treatment, the two aqueous solutions containing an antibiotic or a local anesthetic would be sprayed on and form a gel in situ without the need for direct contact with the burn.

The following examples further illustrate the disclosure and are not intended to limit the scope. It is to be understood that this disclosure is not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present disclosure will be limited only by the appended claims.

6. EXAMPLES

6.1. Preliminary Investigations into Two-Component Gel

While investigating different nozzles for oocyst vaccine application to day-old chicks, a method was sought for visualizing the spray patterns produced by the nozzles. Water sensitive paper cards (Syngenta) were used initially, but the patterns formed were found to be subject to bounce, especially near the center of the spray. As an alternative, a method was developed in which a petri dish was loaded with a 2-mL pool of 2% sodium alginate. The spray solution incorporated about 3% calcium chloride, red food coloring, and, in some cases, an oocyst vaccine. The spray was delivered from the nozzle into the sodium alginate pool where a red gel formed upon contact of the two solutions. While analyzing the resulting gel patterns, and especially after visualizing the oocysts contained within the gel under the microscope, the option of using this two-component gel system to deliver the vaccine to the bird was developed. The gel forms a protective barrier around the oocysts and potentially allow the oocysts to be available for preening for a longer period. Both components of the formulation are low viscosity, which is an advantage over high viscosity gel formulations currently used for oocyst vaccine delivery. The low viscosity aqueous solutions offer advantages over the current high viscosity gels including ease and uniformity of dispersion and ease of dispense. In addition to protecting the vaccine components, the gel formulation is expected to reduce bounce and aid in maintaining the vaccine or substance administered on the vaccinated subject.

Initial experiments delivering vaccine to chicks via the two-component gel method used 3% calcium chloride and 2% sodium alginate. In some cases, the gel was observed to lose stability after a few minutes on the feathers of the chicks. Increasing the calcium chloride concentration from 3% to 5% yielded a thicker gel which held its structure more uniformly and would likely form a more protective environment for oocysts or sporocysts. Alginate was dispensed on a petri dish, and solutions of 3, 4, or 5% calcium chloride were applied to the alginate drop. Gels formed immediately. When the plate was tipped upward, however, the gel from the 3% calcium chloride combination ran down the plate, while the 4 and 5% calcium chloride gels stayed in place. Calcium chloride concentrations between about 3.5 and 3.8% are now used.

6.2. Gel Delivery of a Vaccine

Day of hatch broiler chickens were administered a 1× dose of a coccidiosis vaccine by eye drop (positive control) or eye spray. The eye spray used birds placed in a static position between two nozzles. The nozzles used an atomizing air configuration. Sprays were directed toward the eyes of the chicken. Treatments included a mixture of released sporocysts with residual oocysts, produced through manual shaking with glass beads. For additional details see PCT Application No. PCT/US19/41178, filed on Jul. 10, 2019, James Hutchins et al. For one treatment, two sets of nozzles were employed, with the first set administering a 2% sodium alginate solution and the second set administering vaccine in 3.5% calcium chloride solution. Vaccine administered by spray was provided in a total volume of 100 uL (50 uL per eye). Vaccine administered by eye drop was provided in a total of 50 uL (25 uL per eye). An untreated group was also included. After vaccine administration, birds were placed in cages and grown under standard conditions until day 7. Birds were euthanized and intestinal contents were harvested from each bird on day 7. Oocysts in the feces were enumerated by the McMaster's floatation chamber technique. Infectivity rates are tabulated below.

TABLE 1 Infectivity rates by species for chickens vaccinated by eye spray Frequency of Response Amplitude of Response Eye Spray (Birds infected/Birds vaccinated) (Average oocyst output per bird) Treatment E. maxima E. tenella E. acervulina E. maxima E. tenella E. acervulina No Gel 11/14 (79%) 11/14 (79%) 12/14 (86%) 2.83 × 10⁵ 2.70 × 10⁵ 1.04 × 10⁵ Gel 14/15 (93%) 12/15 (80%)  15/15 (100%) 3.37 × 10⁵ 3.38 × 10⁴ 2.61 × 10⁵ Improvement 14% 1% 14% 1.2-fold none 2.5-fold

Results indicate improved infectivity in the gel treatment, especially for E. maxima and E. acervulina. Positive and negative control results were according to expectations.

6.3. Gel Delivery of a Vaccine Containing Sporocysts

In another experiment, the differences between vaccinating with sporocyst versus oocyst can be seen. In this experiment, the release of sporocysts was achieved by shaking a multi-species oocyst suspension with 4 mm glass beads by hand. This sporocyst/residual oocyst solution and oocyst-only solution were administered to a day of hatch aimed at their facial mucosa. Two sets of nozzles were employed, with the first set administering a 2% sodium alginate solution and the second set administering vaccine in 3.0% calcium chloride solution. When these two solutions come into contact on the surface of the bird a gel is formed. The creation of gel is hypothesized to keep the oocyst/sporocyst vaccine hydrated longer as compared to a typical aqueous spray, extending the potential preening time for the birds. The results from this experiment can be seen in the table below.

TABLE 2 Frequency and amplitude of response for birds sprayed with oocysts or sporocysts with residual oocysts in a gel Frequency of Response Amplitude of Response Gel Spray (Birds infected/Birds vaccinated) (Average oocyst output per bird) Treatment E. maxima E. tenella E. acervulina E. maxima E. tenella E. acervulina Oocysts 6/15 (40%) 7/15 (47%) 13/15 (87%)  7.67 × 10⁴ 1.26 × 10⁵ 8.46 × 10⁴ Sporocysts 15/15 (100%) 15/15 (100%) 15/15 (100%) 2.51 × 10⁵ 4.83 × 10⁵ 1.90 × 10⁵ Improvement 60% 53% 13% 3.3-fold 3.8-fold 2.24-fold

No oocysts were observed in the intestinal contents of the untreated control birds, and positive controls, inoculated via eyedrop, yielded infectivity frequencies and amplitudes higher than those of the experimental spray treatment groups. These results indicate that gel formulation sporocyst outperformed oocyst only in both frequency and amplitude of response.

7. GENERALIZED STATEMENTS OF THE DISCLOSURE

The following numbered statements provide a general description of the disclosure and are not intended to limit the appended claims.

Statement 1: A system for delivering a gel to a surface comprising: a first vessel containing a binder/crosslinking agent in a first solution; a second vessel containing a gelling component in a second solution; and a delivery device in fluid communication with the first and second vessels, the delivery device having a delivery device outlet.

Statement 2: The system of Statement 1, whereby when the first solution is moved from the first vessel to the delivery device outlet to create a first spray on a fixed location, and the second solution is moved from the second vessel to the delivery device outlet to create a second spray on the fixed location, the first and second solutions react to form a gel at the fixed location.

Statement 3: The system of any of Statements 1-2, wherein the gelling component is sodium alginate and the binder/crosslinking agent is calcium chloride.

Statement 4: The system of any of Statements 1-3, wherein the first solution or the second solution further comprise a product of interest as either a solution or a suspension.

Statement 5: The system of Statement 4, wherein the product of interest has application in at least one of a group of industries consisting of: food, agricultural, manufacturing, chemical, biochemical, military, aerospace, pharmaceutical, nutraceutical, cosmetic, printing, or a combination thereof.

Statement 6: The system of Statement 4, wherein the product of interest is an edible, a herbicide, a pesticide, a medicine, a biologic, a cosmetic, a nutraceutical, a pharmaceutical, a coating, an ink, a paint, or a combination thereof.

Statement 7: The system of Statement 4, wherein the product of interest is a vaccine.

Statement 8: The system of Statement 7, wherein the vaccine comprises oocysts.

Statement 9: The system of any of Statements 7-8, wherein the vaccine comprises sporocysts.

Statement 10: The system of Statement 3, wherein the calcium chloride is present in a concentration from about 1% to about 5%.

Statement 11: The system of Statement 3, wherein the sodium alginate is present in a concentration from about 0.5% to about 5%.

Statement 12: The system of any of Statements 1-11, wherein the delivery device is a sprayer.

Statement 13: A method for delivering a gel to a surface comprising the steps: providing a first vessel containing a binder/crosslinking agent in a first solution; providing a second vessel containing a gelling component in a second solution; providing a delivery device in fluid communication with the first and second vessels; moving the first solution from the first vessel through the delivery device outlet and onto a surface at a fixed location; and moving the second solution from the second vessel through the delivery device outlet and onto the surface at the fixed location to form a gel.

Statement 14: The method of Statement 13, wherein the first solution or the second solution further comprise a product of interest as either a solution or a suspension.

Statement 15: The method of Statement 14, wherein the product of interest has application in at least one of a group of industries consisting of: food, agricultural, manufacturing, chemical, biochemical, military, aerospace, pharmaceutical, cosmetic, nutraceutical, printing, or a combination thereof.

Statement 16: The method of Statement 14, wherein the product of interest is an edible, a herbicide, a pesticide, a medicine, a biologic, a cosmetic, a nutraceutical, a pharmaceutical, a coating, an ink, a paint, a dye, or a combination thereof.

Statement 17: The method of Statement 14, wherein the product of interest is a vaccine.

Statement 18: The method of Statement 17, wherein the vaccine comprises oocysts.

Statement 19: The method of any of Statements 17-18, wherein the vaccine comprises sporocysts.

Statement 20: A gel solution formed in situ wherein the gel is formed by a first solution containing a binder/crosslinking agent applied to a surface at a fixed location and a second solution containing a gelling component applied to the surface at the fixed location.

It should be understood that the above description is only representative of illustrative embodiments and examples. For the convenience of the reader, the above description has focused on a limited number of representative examples of all possible embodiments, examples that teach the principles of the disclosure. The description has not attempted to exhaustively enumerate all possible variations or even combinations of those variations described. That alternate embodiments may not have been presented for a specific portion of the disclosure, or that further undescribed alternate embodiments may be available for a portion, is not to be considered a disclaimer of those alternate embodiments. One of ordinary skill will appreciate that many of those undescribed embodiments, involve differences in technology and materials rather than differences in the application of the principles of the disclosure. Accordingly, the disclosure is not intended to be limited to less than the scope set forth in the following claims and equivalents.

INCORPORATION BY REFERENCE

All references, articles, publications, patents, patent publications, and patent applications cited herein are incorporated by reference in their entireties for all purposes. However, mention of any reference, article, publication, patent, patent publication, and patent application cited herein is not, and should not be taken as an acknowledgment or any form of suggestion that they constitute valid prior art or form part of the common general knowledge in any country in the world. It is to be understood that, while the disclosure has been described in conjunction with the detailed description, thereof, the foregoing description is intended to illustrate and not limit the scope. Other aspects, advantages, and modifications are within the scope of the claims set forth below. All publications, patents, and patent applications cited in this specification are herein incorporated by reference as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. 

What is claimed is:
 1. A system for delivering a gel to a surface comprising: a first vessel containing a binder/crosslinking agent in a first solution; a second vessel containing a gelling component in a second solution; and a delivery device in fluid communication with the first and second vessels, the delivery device having a delivery device outlet.
 2. The system of claim 1 whereby when the first solution is moved from the first vessel to the delivery device outlet to create a first spray on a fixed location, and the second solution is moved from the second vessel to the delivery device outlet to create a second spray on the fixed location, the first and second solutions react to form a gel at the fixed location.
 3. The system of claim 1, wherein the gelling component is sodium alginate and the binder/crosslinking agent is calcium chloride.
 4. The system of claim 1, wherein the first solution or the second solution further comprise a product of interest as either a solution or a suspension.
 5. The system of claim 4, wherein the product of interest has application in at least one of a group of industries consisting of: food, agricultural, manufacturing, chemical, biochemical, military, aerospace, pharmaceutical, nutraceutical, cosmetic, printing, or a combination thereof.
 6. The system of claim 4, wherein the product of interest is an edible, a herbicide, a pesticide, a medicine, a biologic, a cosmetic, a nutraceutical, a pharmaceutical, a coating, an ink, a paint, or a combination thereof.
 7. The system of claim 4, wherein the product of interest is a vaccine.
 8. The system of claim 7, wherein the vaccine comprises oocysts.
 9. The system of claim 7, wherein the vaccine comprises sporocysts.
 10. The system of claim 3, wherein the calcium chloride is present in a concentration from about 1% to about 5%.
 11. The system of claim 3, wherein the sodium alginate is present in a concentration from about 0.5% to about 5%.
 12. The system of claim 1, wherein the delivery device is a sprayer.
 13. A method for delivering a gel to a surface comprising the steps: providing a first vessel containing a binder/crosslinking agent in a first solution; providing a second vessel containing a gelling component in a second solution; providing a delivery device in fluid communication with the first and second vessels; moving the first solution from the first vessel through the delivery device outlet and onto a surface at a fixed location; and moving the second solution from the second vessel through the delivery device outlet and onto the surface at the fixed location to form a gel.
 14. The method of claim 13, wherein the first solution or the second solution further comprise a product of interest as either a solution or a suspension.
 15. The method of claim 14, wherein the product of interest has application in at least one of a group of industries consisting of: food, agricultural, manufacturing, chemical, biochemical, military, aerospace, pharmaceutical, cosmetic, nutraceutical, printing, or a combination thereof.
 16. The method of claim 14, wherein the product of interest is an edible, a herbicide, a pesticide, a medicine, a biologic, a cosmetic, a nutraceutical, a pharmaceutical, a coating, an ink, a paint, a dye, or a combination thereof.
 17. The method of claim 14, wherein the product of interest is a vaccine.
 18. The method of claim 17, wherein the vaccine comprises oocysts.
 19. The method of claim 17, wherein the vaccine comprises sporocysts.
 20. A gel solution formed in situ wherein the gel is formed by a first solution containing a binder/crosslinking agent applied to a surface at a fixed location and a second solution containing a gelling component applied to the surface at the fixed location. 